From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754842AbdCGIH7 (ORCPT ); Tue, 7 Mar 2017 03:07:59 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:53637 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754593AbdCGIHo (ORCPT ); Tue, 7 Mar 2017 03:07:44 -0500 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 165.244.249.25 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org From: Minchan Kim To: Andrew Morton CC: , , , Minchan Kim , Vlastimil Vlastimil Babka , Michal Hocko , "Kirill A . Shutemov" , Johannes Weiner , Chen Gang Subject: [PATCH] mm: Do not use double negation for testing page flags Date: Tue, 7 Mar 2017 15:36:37 +0900 Message-ID: <1488868597-32222-1-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 2.7.4 X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/03/07 15:36:45, Serialize by Router on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/03/07 15:36:45, Serialize complete at 2017/03/07 15:36:45 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the discussion[1], I found it seems there are every PageFlags functions return bool at this moment so we don't need double negation any more. Although it's not a problem to keep it, it makes future users confused to use dobule negation for them, too. Remove such possibility. [1] https://marc.info/?l=linux-kernel&m=148881578820434 Frankly sepaking, I like every PageFlags return bool instead of int. It will make it clear. AFAIR, Chen Gang had tried it but don't know why it was not merged at that time. http://lkml.kernel.org/r/1469336184-1904-1-git-send-email-chengang@emindsoft.com.cn Cc: Vlastimil Vlastimil Babka Cc: Michal Hocko Cc: Kirill A. Shutemov Cc: Johannes Weiner Cc: Chen Gang Signed-off-by: Minchan Kim --- mm/khugepaged.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 88e4b17..7cb9c88 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -548,7 +548,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * The page must only be referenced by the scanned process * and page swap cache. */ - if (page_count(page) != 1 + !!PageSwapCache(page)) { + if (page_count(page) != 1 + PageSwapCache(page)) { unlock_page(page); result = SCAN_PAGE_COUNT; goto out; @@ -1181,7 +1181,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, * The page must only be referenced by the scanned process * and page swap cache. */ - if (page_count(page) != 1 + !!PageSwapCache(page)) { + if (page_count(page) != 1 + PageSwapCache(page)) { result = SCAN_PAGE_COUNT; goto out_unmap; } -- 2.7.4